• Journal of Animal Science and Technology
• /
• 제61권6호
• /
• pp.324-332
• /
• 2019

This study aimed to identify the causality between climatic and soil variables affecting the yield of Italian ryegrass (Lolium multiflorum Lam., IRG) in the paddy field by constructing the pathways via structure equation model. The IRG data (n = 133) was collected from the National Agricultural Cooperative Federation (1992-2013). The climatic variables were accumulated temperature, growing days and precipitation amount from the weather information system of Korea Meteorological Administration, and soil variables were effective soil depth, slope, gravel content and drainage class as soil physical properties from the soil information system of Rural Development Administration. In general, IRG cultivation by the rice-rotation system in paddy field is important and unique in East Asia because it contributes to the increase of income by cultivating IRG during agricultural off-season. As a result, the seasonal effects of accumulated temperature and growing days of autumn and next spring were evident, furthermore, autumnal temperature and spring precipitation indirectly influenced yield through spring temperature. The effect of autumnal temperature, spring temperature, spring precipitation and soil physics factors were 0.62, 0.36, 0.23, and 0.16 in order (p < 0.05). Even though the relationship between soil physical and precipitation was not significant, it does not mean there was no association. Because the soil physical variables were categorical, their effects were weakly reflected even with scale adjustment by jitter transformation. We expected that this study could contribute to increasing IRG yield by presenting the causality of climatic and soil factors and could be extended to various factors.

• 한국작물학회지
• /
• 제49권4호
• /
• pp.309-315
• /
• 2004

This study was carried out to evaluate the seed quality of soybeans produced from upland and drained-paddy fields. Soybeans from drained-paddy field showed significantly higher in the 100 seeds weight and greater in the size of seed length than those from upland fields. However, there are no significant differences in seed width and thickness between upland and paddy fields. In case of Hunter's color value, the lightness (L) was significantly higher in the upland soybeans, but the a (redness) and b (yellowness) values were higher in the drained-paddy field soybeans. Seed appearance of drained-paddy field was poor than that of upland field. Soybeans produced from the drained-paddy field showed higher protein content, whereas, lipid and ash contents were higher in the upland field. Soybeans from upland field had lower contents of total amino acids compared to drained-paddy fields. No statistical differences were found in palmitic, linoleic, and linolenic, but stearic, oleic, saturated fatty acids (SFA), and unsaturated fatty acids (USFA) showed significant differences between soybean seeds from upland and drained-paddy fields. Genistein content was higher in the drained-paddy fields, while daidzein and glycitein contents were higher in the upland fields. This result suggested that the soil condition of drained-paddy field is more favorable to synthesis genistein than daidzein and glycitein.

• 한국작물학회지
• /
• 제50권6호
• /
• pp.387-393
• /
• 2005

2002년부터 2004년까지 수원의 작물과학원 논포장을 년차간 순차적으로 밭으로 전환하고 또 밭상태에서 우분을 누적투 입하면서 호밀과 옥수수의 윤작을 통하여 질소와 관련된 토양 특성, 작물의 건물수량 및 질소흡수량을 조사하였는데, 주요 결과는 다음과 같다. 논의 밭전환 1년차에는 밭사료작물, 특히 답리작 호밀의 생육과 수량이 현저히 감소하였으며, 그에 따라 우분시용에 의한 무기태질소 등 양분의 이용효율도 현저히 감소하였다. 그러나 전환년차의 증가와 함께 밭사료작물의 수량과 질소흡수량이 증가하였는데, 특히 밭상태에서 전환3년차까지 우분의 누적투입은 토양에의 무기태 질소공급과 더불어 옥수수의 수량, 질소흡수량 및 우분질소 이용률을 계속적으로 증가시켰다. 그 증가는 전환년차 증가에 따른 논토양 자체의 질소공급보다는 주로 우분시용에 의한 토양물리성 개선, 토양탄소 및 무기화 가능한 지력질소(가급태질소) 증가 등 지력증진에 크게 기인하였다. 따라서 전환밭에서 정상적인 밭사료작물의 수량을 얻기 위해서는 전환2년 이상의 기간이 필요하였으며, 이때 우분의 투입은 토양에 무기태질소 공급뿐만아니라 토양유기물 등 지력증진에도 효과적이었으며, 또한 그것이 누적적으로 투입될 때 그 효과가 증가되는 것으로 나타났다.

• Journal of Biosystems Engineering
• /
• 제27권2호
• /
• pp.133-142
• /
• 2002

This is a fundamental study to develop a sensor to detect weeds in paddy field using machine vision adopted spectralphotometric technique in order to use the sensor to spread herbicide selectively. A set of spectral reflectance data was collected from dry and wet soil and leaves of rice and 6 kinds of weed to select desirable wavelengths to classify soil, rice and weeds. Stepwise variable selection method of discriminant analysis was applied to the data set and wavelengths of 680 and 802 m were selected to distinguish plants (including rice and weeds) from dry and wet soil, respectively. And wavelengths of 580 and 680 nm were selected to classify rice and weeds by the same method. Validity of the wavelengths to distinguish the plants from soil was tested by cross-validation test with built discriminant function to prove that all of soil and plants were classified correctly without any failure. Validity of the wavelengths for classification of rice and weeds was tested by the same method and the test resulted that 98% of rice and 83% of weeds were classified correctly. Feasibility of CCD color camera to detect weeds in paddy field was tested with the spectral reflectance data by the same statistical method as above. Central wavelengths of RGB frame of color camera were tried as tile effective wavelengths to distingush plants from soil and weeds from plants. The trial resulted that 100% and 94% of plants in dry soil and wet soil, respectively, were classified correctly by the central wavelength or R frame only, and 95% of rice and 85% of weeds were classified correctly by the central wavelengths of RGB frames. As a result, it was concluded that CCD color camera has good potential to be used to detect weeds in paddy field.

• 미생물학회지
• /
• 제34권3호
• /
• pp.149-153
• /
• 1998

산림, 밭, 초지, 논 토양의 두 깊이(0~2cm, $50{\pm}1cm$)에서 계절별로 채취한 토양 시료로부터 서로 다른 방선균주를 분리, 동정하여 계절별 토양 방선균의 속 다양성을 조사하였다. 토양 표층에 분포하는 Streptomyces속 방선균주의 계절별 변동율은 논(18%)과 산림(18%) 토양에 비해 초지(41%)와 밭(39%) 토양에서 더 높게 나타났으며 $50{\pm}1cm$깊이에서는 논(36%), 밭(28%), 초지(26%), 산림(16%) 토양 순으로 높게 나타났다. 한편 희소 방선균의 계절별 분포 변동율을 토양 표층의 경우 논 토양(26%)을 제외하고는 모두 45%이상이었으나 $50{\pm}1cm$깊이에서는 산림(79%), 논(36%), 밭(24%), 초지(10%) 토양 순으로 높게 나타났다. 따라서, 토양 중에 분포하는 방선균의 속 다양성은 계절 변화에 의지하며 또한 이는 방선균군의 종류, 토양의 유형, 그리고 토양 깊이에 의해서 영향을 받을 것으로 고려된다.

• 한국토양비료학회지
• /
• 제48권2호
• /
• pp.146-152
• /
• 2015

Heavy metal pollution has been a critical problem in agricultural field near at the abandoned metal mines and chemical amendments are applied for remediation purpose. However, biological activity can be changed depending on chemical amendments affecting crop productivity. Main purpose of this research was to evaluate biological parameters after applying chemical amendments in heavy metal polluted agricultural field. Result showed that soil respiration (SR) and microbial biomass carbon (MBC) were changed after chemical amendments were applied. Among three different amendments, lime stone (LS), steel slag (SS), and acid mine drainage sludge(AMDS), AMDS had an effect to increase SR in paddy soil. Comparing to control ($93.98-170.33mg\;kg^{-1}day^{-1}$), average of 30% increased SR was observed. In terms of MBC, SS had an increased effect in paddy soil. However, no significant difference of SR and MBC was observed in upland soil after chemical amendment application. Overall, SR can be used as an indicator of heavy metal remediation in paddy soil.

• 한국환경과학회지
• /
• 제20권8호
• /
• pp.963-975
• /
• 2011

For this research, they were monitored $CO_2$ flux and environmental factors ($CO_2$ concentration, soil temperature, soil moisture, soil organic carbon, soil pH, soil Eh) in foreshore, paddy field and woods sites at the winter season (January 2009) and the summer season (September 2009). Seasonal and spatial variations for monitored data were analyzed, and linear regression functions of $CO_2$ flux as environmental factors were estimated. $CO_2$ fluxes averaged between surface and atmosphere monitored in foreshore and paddy field at the winter season were shown $-8\;mgCO_2m^{-2}hr^{-1}$ and $-25\;mgCO_2m^{-2}hr^{-1}$, respectively. $CO_2$ fluxes averaged between surface and atmosphere monitored in foreshore and paddy field at the summer season were shown $47\;mgCO_2m^{-2}hr^{-1}$ and $117\;mgCO_2m^{-2}hr^{-1}$, respectively. Thus, $CO_2$ was sunk from atmosphere to surface at the winter season and it was emitted from surface to atmosphere at the summer season. $CO_2$ fluxes in woods site were emitted $145\;mgCO_2m^{-2}hr^{-1}$ at the winter season and $279\;mgCO_2m^{-2}hr^{-1}$ at the summer season.

• 한국미생물·생명공학회지
• /
• 제23권1호
• /
• pp.36-42
• /
• 1995

Actinomycetes occur in a wide range of environments and many more actinomycetes remain to be detected in the natural environment. In isolation stages, selection of the environment as a source of useful isolates is important. Two hundred and eighteen strains were isolated on Bennet's agar and 346 strains were on humic acid-vitamin agar from five each paddy field, field, forest, grass land, riverside soil samples. These isolates were identified to the genus level based on morphological and physiological characteristics. Among them, 386 strains were Streptomyces, 49 strain were Nocardia, 35 strains were Microbispora and Micromonospora each, 15 strains were Nocardiopsis, 13 strains were Actinomadura, 10 strains were Streptosporangium, and the others were isolated rarely. According to soil type, Nocardia, Micromonospora, Microbispora and Streptosporangium were dominant in paddy field, Microbispora Nocardia, Nocardioides and Micromonospora were dominant in field, Nocardia, Micromonospora, Microbispora and Actinomadura were dominant in grass land, Nocardia, Micromonospora and Microbispora were dominant in forest, Nocardia, Microbispora and Micromonospora were dominant in riverside. Generally, Nocardia, Micromonospora, Microbispora and Actinomadura were isolated in all kinds of soils, Streptosporangium were paddy field, Dactylosporangium were forest, Nocardiopsis were field, forest and riverside.

• 미생물학회지
• /
• 제46권4호
• /
• pp.319-325
• /
• 2010

여름과 가을의 논과 밭 토양의 토양성분과 메탄 생성, 메탄 생성세균의 분포, 그리고 메탄생성세균의 군집구조를 조사하였다. 토양성분을 분석한 결과, 전체적으로 계절에 따라 큰 변화는 나타나지 않았다. 메탄생성세균의 분포조사에서 밭 토양보다 유기농법과 무농약농법을 사용하는 논 토양에 메탄생성세균이 더 많이 존재하였고, 수소와 포름산을 이용하는 메탄생성세균에 비해 아세트산을 이용하는 메탄생성세균 수는 상대적으로 적은 것으로 확인되었다. 메탄생성 실험에서 아세트산을 첨가한 경우 배양 2주까지 메탄생성이 증가되었고, 포름산과 수소를 첨가한 경우 배양 7주까지 메탄생성 양이 증가되었다. mcrA 유전자를 이용한 계통학적 분석에서 논에는 다양한 메탄 생성세균의 cluster가 분포하는 반면, 밭에는 일부 cluster에 집중되어 분포함을 확인하였다.

• 한국토양비료학회지
• /
• 제45권6호
• /
• pp.1043-1048
• /
• 2012

돈분액비의 시용법이 벼재배시 토양과 생육에 미치는 영향을 비교하고자 미사질양토 논에서 각각의 시용법에 따라 돈분액비를 논토양에 시용하여 토양의 이화학적 특성과 벼 생육 및 수량을 조사하였다. 사용된 돈분액비의 유효성분 함량은 질소 0.44%, 인산 0.07%, 가리 0.14%였으며, 벼 표준시비량에 준하여 10a당 6.8톤을 기비와 추비로 나누어 시비하였다. 액비 시비 후 토양의 이화학성은 처리구간에 큰 차이가 없었다. 질소 함량은 관수혼입 추비구에서 다소 높았으나 균일성이 떨어지고 혼입부에 벼의 도장이 발생하였다. 액비 시비 후 경시적인 암모니아 가스발생은 살포량이 많을수록 높았으며 살포 당일에 가장 높았고, 써레질 후에는 거의 발생하지 않았다. 벼의 수량은 담수 기비구보다 건답 기비구에서 증수되었으나 처리구간에 큰 차이는 없었으며, 제트분무 추비구에서는 유수형성기에 과도한 질소공급으로 영양생장을 지속하여 등숙율이 약 20% 저하되었고 식물체에 물리적 피해도 나타났다. 가장 적은 수확량을 보인 담수 기비+제트분무 추비구와 비교하여 건답 기비+관수혼입 추비구에서 9.6% 증수되었다.